关节镜半月板治疗膝骨关节炎对治疗有效率、VAS评分、HSS评分及TNF-α指标水平的应用研究

目的分析关节镜半月板治疗膝骨关节炎对治疗有效率、VAS评分、HSS评分及TNF-α指标水平的影响。方法选择2019年6月—2020年5月在我院进行治疗的86例因半月板损伤引起膝骨关节炎的患者作为研究对象,根据患者的意愿选择治疗方式,其中43例选择常规保守治疗的患者纳入对照组,另外43例选择关节镜半月板治疗的患者纳入研究组。对两组患者的治疗有效率、视觉模拟评分法(VAS)评分、HSS膝关节评分及肿瘤坏死因子-α(TNF-α)指标水平进行比较。结果研究组的治疗有效率显著高于对照组(P<0.05);研究组与对照组在治疗前的VAS评分、HSS评分、TNF-α水平进行比较均无显著差异(P>0.05),两组经治疗后的VAS评分、HSS评分及TNF-α水平均得到了改善,研究组在治疗后的VAS评分、TNF-α指标水平均低于对照组(P<0.05),HSS评分高于对照组(P<0.05)。结论对膝骨关节炎患者采取关节镜半月板治疗,具有显著效果,可有效减轻患者的疼痛程度与炎症反应,提升膝关节功能。

基于HSS-MCC融合模型及SSA-BP神经网络开展深基坑超大变形预测研究

软土环境下深基坑开挖变形特性研究中,多采用硬化类弹塑性模型进行分析,如HSS模型和MCC模型.南京河漫滩软土地区,深基坑开挖时局部常发生较大变形,部分土体变形状态介于小应变与大应变之间,单一模型无法准确预测土体变形特征.同时,BP神经网络在基坑变形预测中得到广泛应用,但在训练过程中,权阈值易陷入局部最优解,影响预测的准确性.据此,依托南京地区典型软土深基坑工程,采用Midas中的HSS模型与MCC模型进行分析,比对两种模型的桩体变形量差异,并基于最小二乘准则对两模型进行线性融合,融合模型可对后续区段监测数据进行校准及补充.通过融合麻雀搜索算法对BP神经网络进行优化,在其训练过程中快速收敛,得到全局最优的权阈值,依托狭长基坑已开挖区段监测数据学习训练,进而依据后续区段浅部开挖揭露深部变形特征,预测结果与实测值吻合度较高.研究结果对软土地区深基坑大变形的预测研究具有重要参考价值.

基于HSS模型海上风电桶形基础水平循环承载特性对比研究

采用土体本构模型对黏土中的桶形基础进行了有限元模拟,以研究桶形基础的水平循环承载特性。利用有限元方法模拟了在不同单调组合荷载作用下黏土中的桶形基础离心机试验,与试验结果对比验证了使用小应变硬化土(HSS)本构模型的适用性。在此基础上,基于HSS模型和硬化土(HS)模型对比研究了不同循环荷载和小应变模量对桶形基础累积转角、旋转中心和桶-土相对刚度的影响。结果表明,黏土中桶形基础的累积转角随着循环次数和水平荷载的增加而增加,然而每个循环中累积转角的增加逐渐减小。另外,提出了Tb和ζb之间的拟合关系式预测黏土中桶形基础的累积旋转。无论处于疲劳极限状态(ζb=0.3)还是正常使用极限状态(ζb=0.5),旋转中心类型都是从深中心变为浅中心。桶-土相对刚度随循环次数的增加而减小,并且循环荷载越大刚度衰减越大。另外,小应变模量对基础累积转角和桶-土相对刚度有较大影响而对旋转中心无显著影响。与已有的研究结果对比发现,HSS模型更加适用于精细化设计。

济南济泺路穿黄隧道典型粉质黏土HSS模型参数获取及适用性

盾构施工过程中土体大部分区域处于小应变状态,与常用的本构模型的土体性质有所不同。因此,为研究济南济泺路穿黄隧道区域内典型粉质黏土的的静动力行为特性及工程适用性,通过室内基础土工试验、侧限固结试验、标准三轴固结试验以及动三轴试验,确定了粉质黏土基本物理性质参数以及切线刚度E_(oed)^(ref)、割线模量E_(50)^(ref)、卸载/重加载参考刚度E_(ur)^(ref),并将所得参数应用于济南济泺路穿黄隧道工程下穿北岸大堤沉降分析中,同时通过对比应用硬化土小应变硬化(hardening soil model with small strain stiffness,HSS)本构模型、摩尔库伦(M-C)本构模型的模拟结果与现场实测结果,验证了HSS本构模型在该地区变形分析中的准确性。结果表明:围压一定时,该地区粉质黏土试样竖向应变以塑性应变为主,且随动应力的增加,土体达到稳定所需时间越长;循环荷载一定时,增大土体围压可提高土体的稳定性;基于室内试验获取的HSS本构模型参数模拟的济南济泺路穿黄隧道下穿大堤工程地层变形结果与现场实测值吻合良好,验证了基于所提出的室内试验获取岩土小应变相关参数方法的适用性。研究成果可以丰富济南黄河地区粉质黏土地层参数研究,并为该地区岩土工程数值模拟分析的本构模型与地层参数选取提供参考。

基于HSS模型双线隧道上跨施工对既有地铁影响

针对某新建盾构隧道近接上跨既有地铁项目,基于小应变硬化模型(HSS),建立了三维有限元模型,通过与实测数据和莫尔–库伦模型计算结果的对比,验证了HSS模型计算的可靠性和优越性。在此基础上,进一步分析了新建隧道施工引起的既有隧道竖向变形特征,及隧道水平净距和叠交角度两参数对既有隧道变形的影响规律。结果表明:HSS模型计算结果与实测值吻合较好,能有效预测既有地铁隧道的变形;在新建隧道上跨穿越的影响下,既有地铁隧道产生竖向隆起变形,且变形主要发生在盾构下穿前的1.5倍新建隧道直径到穿越后的2倍新建隧道直径范围内;既有地铁隧道隆起峰值点会随着盾构二次穿越而发生偏移,且其竖向变形曲线呈现出“双峰”趋势;增大双线隧道水平净距和新旧隧道叠交角度,都能使既有隧道的变形减小。

A Review on Sources,Extractions and Analysis Methods of a Sustainable Biomaterial:Tannins

Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products.They are a definite class of sustainable materials of the forestry industry.They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries,such as wood adhesives,metal coating,pharmaceutical/medical applications and several others.This review presents the main sources,either already or potentially commercial of this forestry by-materials,their industrial and laboratory extraction systems,their systems of analysis with their advantages and drawbacks,be these methods so simple to even appear primitive but nonetheless of proven effectiveness,or very modern and instrumental.It constitutes a basic but essential summary of what is necessary to know of these sustainable materials.In doing so,the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses.

Drilling-based measuring method for the c-φ parameter of rock and its field application

The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters.

Efficient slope reliability and sensitivity analysis using quantile-based first-order second-moment method

This paper introduces a novel approach for parameter sensitivity evaluation and efficient slope reliability analysis based on quantile-based first-order second-moment method(QFOSM).The core principles of the QFOSM are elucidated geometrically from the perspective of expanding ellipsoids.Based on this geometric interpretation,the QFOSM is further extended to estimate sensitivity indices and assess the significance of various uncertain parameters involved in the slope system.The proposed method has the advantage of computational simplicity,akin to the conventional first-order second-moment method(FOSM),while providing estimation accuracy close to that of the first-order reliability method(FORM).Its performance is demonstrated with a numerical example and three slope examples.The results show that the proposed method can efficiently estimate the slope reliability and simultaneously evaluate the sensitivity of the uncertain parameters.The proposed method does not involve complex optimization or iteration required by the FORM.It can provide a valuable complement to the existing approximate reliability analysis methods,offering rapid sensitivity evaluation and slope reliability analysis.

A comparison study on structure-function relationship of polysaccharides obtained from sea buckthorn berries using different methods:antioxidant and bile acid-binding capacity

In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods.

Material point method simulation of hydro-mechanical behaviour in twophase porous geomaterials: A state-of-the-art review

The material point method(MPM)has been gaining increasing popularity as an appropriate approach to the solution of coupled hydro-mechanical problems involving large deformation.In this paper,we survey the current state-of-the-art in the MPM simulation of hydro-mechanical behaviour in two-phase porous geomaterials.The review covers the recent advances and developments in the MPM and their extensions to capture the coupled hydro-mechanical problems involving large deformations.The focus of this review is aiming at providing a clear picture of what has or has not been developed or implemented for simulating two-phase coupled large deformation problems,which will provide some direct reference for both practitioners and researchers.

Volumetric lattice Boltzmann method for pore-scale mass diffusionadvection process in geopolymer porous structures

Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advection process within porous structures is essential for material design.In this study,we present advancements in the volumetric lattice Boltzmann method(VLBM)for modeling and simulating pore-scale diffusion-advection of radioactive isotopes within geopolymer porous structures.These structures are created using the phase field method(PFM)to precisely control pore architectures.In our VLBM approach,we introduce a concentration field of an isotope seamlessly coupled with the velocity field and solve it by the time evolution of its particle population function.To address the computational intensity inherent in the coupled lattice Boltzmann equations for velocity and concentration fields,we implement graphics processing unit(GPU)parallelization.Validation of the developed model involves examining the flow and diffusion fields in porous structures.Remarkably,good agreement is observed for both the velocity field from VLBM and multiphysics object-oriented simulation environment(MOOSE),and the concentration field from VLBM and the finite difference method(FDM).Furthermore,we investigate the effects of background flow,species diffusivity,and porosity on the diffusion-advection behavior by varying the background flow velocity,diffusion coefficient,and pore volume fraction,respectively.Notably,all three parameters exert an influence on the diffusion-advection process.Increased background flow and diffusivity markedly accelerate the process due to increased advection intensity and enhanced diffusion capability,respectively.Conversely,increasing the porosity has a less significant effect,causing a slight slowdown of the diffusion-advection process due to the expanded pore volume.This comprehensive parametric study provides valuable insights into the kinetics of isotope uptake in porous structures,facilitating the development of porous materials for nuclear waste treatment applications.

Sparse Modal Decomposition Method Addressing Underdetermined Vortex-Induced Vibration Reconstruction Problem for Marine Risers

When investigating the vortex-induced vibration(VIV)of marine risers,extrapolating the dynamic response on the entire length based on limited sensor measurements is a crucial step in both laboratory experiments and fatigue monitoring of real risers.The problem is conventionally solved using the modal decomposition method,based on the principle that the response can be approximated by a weighted sum of limited vibration modes.However,the method is not valid when the problem is underdetermined,i.e.,the number of unknown mode weights is more than the number of known measurements.This study proposed a sparse modal decomposition method based on the compressed sensing theory and the Compressive Sampling Matching Pursuit(Co Sa MP)algorithm,exploiting the sparsity of VIV in the modal space.In the validation study based on high-order VIV experiment data,the proposed method successfully reconstructed the response using only seven acceleration measurements when the conventional methods failed.A primary advantage of the proposed method is that it offers a completely data-driven approach for the underdetermined VIV reconstruction problem,which is more favorable than existing model-dependent solutions for many practical applications such as riser structural health monitoring.

基于HSS技术的深基坑土体形变规律分析研究

针对深基坑土体形变的问题,提出了一种结合有限元软件和小应变土体硬化模型的数值模型,解决了深基坑工程中土体变形问题,结果实现了深基坑土体形变规律的分析。数值模型研究结果表明:深基坑开挖深度越大,土体水平位移和地表沉降便越大。

Uncertainties of landslide susceptibility prediction: Influences of random errors in landslide conditioning factors and errors reduction by low pass filter method

In the existing landslide susceptibility prediction(LSP)models,the influences of random errors in landslide conditioning factors on LSP are not considered,instead the original conditioning factors are directly taken as the model inputs,which brings uncertainties to LSP results.This study aims to reveal the influence rules of the different proportional random errors in conditioning factors on the LSP un-certainties,and further explore a method which can effectively reduce the random errors in conditioning factors.The original conditioning factors are firstly used to construct original factors-based LSP models,and then different random errors of 5%,10%,15% and 20%are added to these original factors for con-structing relevant errors-based LSP models.Secondly,low-pass filter-based LSP models are constructed by eliminating the random errors using low-pass filter method.Thirdly,the Ruijin County of China with 370 landslides and 16 conditioning factors are used as study case.Three typical machine learning models,i.e.multilayer perceptron(MLP),support vector machine(SVM)and random forest(RF),are selected as LSP models.Finally,the LSP uncertainties are discussed and results show that:(1)The low-pass filter can effectively reduce the random errors in conditioning factors to decrease the LSP uncertainties.(2)With the proportions of random errors increasing from 5%to 20%,the LSP uncertainty increases continuously.(3)The original factors-based models are feasible for LSP in the absence of more accurate conditioning factors.(4)The influence degrees of two uncertainty issues,machine learning models and different proportions of random errors,on the LSP modeling are large and basically the same.(5)The Shapley values effectively explain the internal mechanism of machine learning model predicting landslide sus-ceptibility.In conclusion,greater proportion of random errors in conditioning factors results in higher LSP uncertainty,and low-pass filter can effectively reduce these random errors.

Numerical manifold method for thermo-mechanical coupling simulation of fractured rock mass

As a calculation method based on the Galerkin variation,the numerical manifold method(NMM)adopts a double covering system,which can easily deal with discontinuous deformation problems and has a high calculation accuracy.Aiming at the thermo-mechanical(TM)coupling problem of fractured rock masses,this study uses the NMM to simulate the processes of crack initiation and propagation in a rock mass under the influence of temperature field,deduces related system equations,and proposes a penalty function method to deal with boundary conditions.Numerical examples are employed to confirm the effectiveness and high accuracy of this method.By the thermal stress analysis of a thick-walled cylinder(TWC),the simulation of cracking in the TWC under heating and cooling conditions,and the simulation of thermal cracking of the SwedishÄspöPillar Stability Experiment(APSE)rock column,the thermal stress,and TM coupling are obtained.The numerical simulation results are in good agreement with the test data and other numerical results,thus verifying the effectiveness of the NMM in dealing with thermal stress and crack propagation problems of fractured rock masses.

基于HSS模型邻近建筑的深基坑数值分析

以某邻近既有建筑的深基坑工程为例,利用有限元软件PLAXIS 2D建立数值模型,研究了硬化土小应变模型(HSS模型)与摩尔库伦模型(MC模型)下基坑开挖过程中地连墙水平位移与地表沉降与实际监测数据的差异,并基于HSS模型分析了基坑开挖过程中围护结构水平位移与既有建筑的沉降,同时,本文分析了既有建筑与基坑之间距离以及既有建筑的层数对既有建筑倾斜率的影响。分析结果表明:HSS模型相对于MC模型可以更加精确的预测基坑开挖工程中的变形情况;采用HSS模型模拟时,围护结构的水平位移为“内凸形”,随基坑深度的增加,围护结构最大水平位置不断下移、最大水平位移逐渐增大,围护桩最大水平位移为24.2 mm,建筑物最大沉降为11.9 mm,均满足设计要求;基坑与建筑物之间距离越小,建筑物层数越高,邻近建筑物倾斜率越高,建筑物每增加一层,其倾斜度约增加0.58×10^(-4)。

A stable implicit nodal integration-based particle finite element method(N-PFEM)for modelling saturated soil dynamics

In this study,we present a novel nodal integration-based particle finite element method(N-PFEM)designed for the dynamic analysis of saturated soils.Our approach incorporates the nodal integration technique into a generalised Hellinger-Reissner(HR)variational principle,creating an implicit PFEM formulation.To mitigate the volumetric locking issue in low-order elements,we employ a node-based strain smoothing technique.By discretising field variables at the centre of smoothing cells,we achieve nodal integration over cells,eliminating the need for sophisticated mapping operations after re-meshing in the PFEM.We express the discretised governing equations as a min-max optimisation problem,which is further reformulated as a standard second-order cone programming(SOCP)problem.Stresses,pore water pressure,and displacements are simultaneously determined using the advanced primal-dual interior point method.Consequently,our numerical model offers improved accuracy for stresses and pore water pressure compared to the displacement-based PFEM formulation.Numerical experiments demonstrate that the N-PFEM efficiently captures both transient and long-term hydro-mechanical behaviour of saturated soils with high accuracy,obviating the need for stabilisation or regularisation techniques commonly employed in other nodal integration-based PFEM approaches.This work holds significant implications for the development of robust and accurate numerical tools for studying saturated soil dynamics.

江苏大丰海域海洋土HSS模型主要参数试验研究

小应变硬化土(hardening soil with small strain stiffness,HSS)模型能反映土体在小应变范围内的非线性,广泛应用于土工变形分析。海上风电基础对变形控制要求高,需考虑土体的小应变特性。通过固结试验、三轴固结排水试验、三轴固结排水加卸载试验与共振柱试验,获得了江苏大丰海域海洋土HSS模型主要参数,并建立了HSS模型相关模量参数与土体物理参数之间的关系。试验成果可为海洋土HSS模型分析及参数取值提供重要参考,具有一定的工程价值。

An inverse analysis of fluid flow through granular media using differentiable lattice Boltzmann method

This study presents a method for the inverse analysis of fluid flow problems.The focus is put on accurately determining boundary conditions and characterizing the physical properties of granular media,such as permeability,and fluid components,like viscosity.The primary aim is to deduce either constant pressure head or pressure profiles,given the known velocity field at a steady-state flow through a conduit containing obstacles,including walls,spheres,and grains.The lattice Boltzmann method(LBM)combined with automatic differentiation(AD)(AD-LBM)is employed,with the help of the GPU-capable Taichi programming language.A lightweight tape is used to generate gradients for the entire LBM simulation,enabling end-to-end backpropagation.Our AD-LBM approach accurately estimates the boundary conditions for complex flow paths in porous media,leading to observed steady-state velocity fields and deriving macro-scale permeability and fluid viscosity.The method demonstrates significant advantages in terms of prediction accuracy and computational efficiency,making it a powerful tool for solving inverse fluid flow problems in various applications.

Robustness Study and Superior Method Development and Validation for Analytical Assay Method of Atropine Sulfate in Pharmaceutical Ophthalmic Solution

Background: The robustness is a measurement of an analytical chemical method and its ability to contain unaffected by little with deliberate variation of analytical chemical method parameters. The analytical chemical method variation parameters are based on pH variability of buffer solution of mobile phase, organic ratio composition changes, stationary phase (column) manufacture, brand name and lot number variation;flow rate variation and temperature variation of chromatographic system. The analytical chemical method for assay of Atropine Sulfate conducted for robustness evaluation. The typical variation considered for mobile phase organic ratio change, change of pH, change of temperature, change of flow rate, change of column etc. Purpose: The aim of this study is to develop a cost effective, short run time and robust analytical chemical method for the assay quantification of Atropine in Pharmaceutical Ophthalmic Solution. This will help to make analytical decisions quickly for research and development scientists as well as will help with quality control product release for patient consumption. This analytical method will help to meet the market demand through quick quality control test of Atropine Ophthalmic Solution and it is very easy for maintaining (GDP) good documentation practices within the shortest period of time. Method: HPLC method has been selected for developing superior method to Compendial method. Both the compendial HPLC method and developed HPLC method was run into the same HPLC system to prove the superiority of developed method. Sensitivity, precision, reproducibility, accuracy parameters were considered for superiority of method. Mobile phase ratio change, pH of buffer solution, change of stationary phase temperature, change of flow rate and change of column were taken into consideration for robustness study of the developed method. Results: The limit of quantitation (LOQ) of developed method was much low than the compendial method. The % RSD for the six sample assay of developed method was 0.4% where the % RSD of the compendial method was 1.2%. The reproducibility between two analysts was 100.4% for developed method on the contrary the compendial method was 98.4%.